After completing this video, the learner will understand the use of one-time pads as an encryption algorithm.
- [Voiceover] Wouldn't it be nice is someone would invent…a perfect encryption algorithm that was unbreakable?…Well, someone already did…and it was more than 100 years ago.…The one-time pad, invented by a telegraph expert in 1882…is an example of an unbreakable cipher.…Using the one-time pad is fairly straightforward.…The sender and receiver each have a copy of identical pads…containing strings of random letters.…The pad must be as long as the total of the characters…of all the messages that they will exchange.…
Here's an example of what one page…in the one-time pad might look like.…The sender writes the characters of the message…in plain text on the pad.…If my message was the word SECRET,…I would simply write that out across the top of the pad.…The sender then adds together the characters of the message…and the characters of the key, treating them as numbers.…A is the first letter of the alphabet,…so think of it as the number one.…B is the number two, and so on.…If we encrypt the first letter, S here,…we do it by adding the first letter of the key, which is A.…
This course is part of a six-course series on the CompTIA Security+ exam, and is useful for IT professionals who wish to learn more about information security as well as students preparing to take the Security+ exam.
We are now a CompTIA Content Publishing Partner. As such, we are able to offer CompTIA exam vouchers at a 10% discount. For more information on how to obtain this discount, please download these PDF instructions.
- Choosing encryption algorithms
- Applying symmetric and asymmetric cryptography standards
- Implementing key management, including key exchange and key stretching
- Working with public keys, trust models, and digital certificates
- Using transport encryption protocols
- Securing wireless networks
Skill Level Intermediate
2. Symmetric Cryptography
3. Asymmetric Cryptography
4. Key Management
5. Public Key Infrastructure
6. Transport Encryption
7. Wireless Security
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